Audio processing in multiple latency domains

Abstract

Methods and systems for generating computationally complex audio effects with low latency involve partitioning computation required to produce the effect into two components: a first component to be executed on a low latency signal network; and the second component to be executed simultaneously with the first component on a high latency signal network. For certain effects for which computation is separable into high and low latency functions, such dual signal network execution results in an overall signal latency of the low latency signal network and an overall efficiency of the high latency signal network. The low and high latency signal networks may be implemented on a DSP and a general purpose microprocessor respectively or both networks may be implemented on a single CPU. Simultaneous dual network implementation is especially beneficial in professional audio performance and recording environments.

What is claimed is: 
     
         1 . An audio processing method comprising:
 receiving an audio signal;   partitioning computation required to generate an audio effect on the audio signal into a low latency component and a high latency component;   executing the low latency component on a low latency signal network;   executing the high latency component on a high latency signal network; and   wherein the audio effect is generated with an overall efficiency characterized by the high latency signal network and an overall latency characterized by the low latency signal network.   
     
     
         2 . The method of  claim 1 , wherein the audio effect is generated using a plug-in module in data communication with a digital audio workstation. 
     
     
         3 . The method of  claim 1 , wherein a buffer size of the high latency signal network is greater than a buffer size of the low latency signal network. 
     
     
         4 . The method of  claim 1 , wherein a buffer size of the high latency signal network is between about 512 bytes and about 2048 bytes, and a buffer size of the low latency network is between about 1 and 64 bytes. 
     
     
         5 . The method of  claim 1 , wherein the low latency signal network and the high latency signal network are implemented as a high priority thread and a low priority thread respectively on a single host CPU. 
     
     
         6 . The method of  claim 1 , wherein the low latency signal network is implemented on a DSP and the high latency signal network is implemented a general purpose CPU. 
     
     
         7 . The method of  claim 1 , wherein the audio effect is generated with a latency of less than about 7 milliseconds. 
     
     
         8 . The method of  claim 1 , wherein the audio effect is a reverb and wherein the low latency component includes computation of early reflections and the high latency component includes computation of a tail of the reverb. 
     
     
         9 . The method of  claim 1 , wherein the audio effect is a pitch correction effect and wherein the high latency component includes analysis of the audio signal to identify portions of the audio signal requiring pitch shifting, and the low latency component includes implementation of pitch shifting based on results of the analysis. 
     
     
         10 . The method of  claim 1 , wherein the audio effect is a spectrum analyzer and wherein the high latency component includes FFT analysis of the audio signal. 
     
     
         11 . The method of  claim 1 , wherein the audio effect is a noise reduction effect and the high latency component includes an FFT-based algorithm to separate the signal components from the noise components. 
     
     
         12 . The method of  claim 1 , wherein executing the low latency component and executing the high latency component are performed sequentially. 
     
     
         13 . The method of  claim 1 , wherein executing the low latency component and executing the high latency component are performed in parallel. 
     
     
         14 . A computer program product comprising:
 a computer-readable storage medium with computer program instructions encoded thereon, wherein the computer program instructions, when processed by a computer, instruct the computer to perform a method for generating an audio effect, the method comprising:   receiving an audio signal;   partitioning computation required to generate an audio effect on the audio signal into a low latency component and a high latency component;   executing the low latency component on a low latency signal network;   executing the high latency component on a high latency signal network; and   wherein the audio effect is generated with an overall efficiency characterized by the high latency signal network and an overall latency characterized by the low latency signal network.   
     
     
         15 . A system for generating an audio effect, the system comprising:
 a memory for storing computer-readable instructions; and   a processor connected to the memory, wherein the processor, when executing the computer-readable instructions, causes the system to perform a method for generating the audio effect, the method comprising:
 receiving an audio signal; 
 partitioning computation required to generate an audio effect on the audio signal into a low latency component and a high latency component; 
 executing the low latency component on a low latency signal network; 
 executing the high latency component on a high latency signal network; and 
 wherein the audio effect is generated with an overall efficiency characterized by the high latency signal network and an overall latency characterized by the low latency signal network.